Detachable plate, sheet, or cowl fastening device



June 29, 1948. GQWER 2,444,040

v DETACHABLE PLATE, SHEET, OR COWL: FASTENING DEVICE Filed Dec. 1s,1943r V N VEN TOR.

Marzo H//an 'awer Ar rom/ys Patented June 29, 1948 UNITED STATES PATENToF-FlcE DETACHABLE PLATE. SHIVEE'II?, -0R, COWL FASTENING DEVICE MarionHutton Gower, Seattle, Wash. Application December 1.8, 1943, Serial No.514,772

2 Claims. (01.24-221) 1 My invention relates to the art of detachableplate. sheet, or cowl fastening devices." More particularly my inventionrelates to such fastening means which is characterized by (a) resil-liently and most ilrmly holding together the plates or parts to be securedof an airplane in sliding contact to accommodate weaving of theparts, (b) .relative ease of securing and unsecuring the device, and (c)economy of manufacture and installation.

The metallic skin covering of an airplane is provided with coveredopenings through which openings access to the mechanism of the airplanemay be had. Coverings for these openings must be of a character readilypermitting detachably securing in closed position An airplane inmaneuvering develops stress or strain of varying magnitude which resultsin much weaving and warping of the parts all of which must be taken intoaccount in providing the fastening means. Such fastening means mustpermit this interL movement of the parts, and yet the partsarepreferably held with such firmness that they do not allow hammeringagainst each other and vibration resulting in noise which may interferewith detecting operative diiliculties such as those oi.' the engine.more of these features and particularly do not possess the necessaryilrmness or stiffness of holding to provide against vibration noises andthey lack economy of manufacture and installation. In providing for theseveral features above set forth, there must not be sacrificedvreadiness of securing and unsecuring, sliding' contact between theplates, and reliability of securing.

Furthermore, as these fastening means are emtogether;

Devices in common use lack one or' l ployed in relatively large numbers,economy of manufacture and installation are particularly important,especially-during war time when utmost efficiency both as toinstallation to save manpower and cost are prime requisites. Objection,particularly, obtains to devices of theprior art respecting theirlcomplicated construction and relatively high cost of installation.

The object of my invention is to provide a fastening means of thecharacter described which particularly meets all of said requirementsand which overcomes all of said objections. '.The spring part ispreferably of a simple U-shaped design with a flattened humpintermediate its ends so that its cost is relatively small and is ofsuch character that its installation is asimple welding operation ratherthan the relatively more expensive riveting operation.

The above mentioned general objects of my 2 invention, together withothers inherent in the same are attained by the device illustrated inthe following drawings, the same being a preferred exemplary form ofembodiment of my invention, throughout which drawings like referencenumerals indicate like parts:

Figure l is a view in perspective of the screw element of my inventionrotatably mounted in a fragment of a plate with a portion of the platebroken away to show the rotatable connection between the groove on theshank of the screw elem'ent and the plate;

Fig. 2 is a view in perspective of the spring of simple U-shaped designwith a flattened hump or raisedv portion intermediate its ends, mountedon a fragment of a second plate member and over the screw receiving portthereof;

'Figa 3 is a view in perspective of parts shown .in Figs. 1 and 2 incombination` and with the screw element in engaging relation securingthe plates Fig. 4 is a fragmentary bottom plan view of the fastenerembodying my invention showing by full and dash lines the sidewisemovement of the spring member occurring while the parts of the tfastenerare being brought into engaging rela ion; i

Fig. 5 is a view partly in elevation and partly in section on brokenline 5-5 of Fig. 4 and indicating by dash lines .the movement of theportion 28 toward plate I9 upon tightening of screw II; Fig. 6'is a viewin section on broken line V6 6 of Fig. 5;

v Fig. 7 isv a detached view of the screw element in a position similarto that shown in Figs. 4 andF; and

Fig. 8 is a'detached viewv of the screw element with the same rotatedtoshow the somewhat `flattened face of the vane of the screw element.

A plate I0, which may be the plate constituating the cowl or covering gfan opening, not shown, in the fuselage of an airplane or otherstructure, rotatably mounts the screw Ii. v The marginal portions Ilprovide a hole or aperture 9 (see Fig. 6) in which is revolvably mountedthe groove I?. of the screw II. Preferably the marginal portions I4 ofthe plate I0 forming the aperture 9 are upturned, as respects theshowing in Fig. 1, and the same may be accomplished by punching. Also,as the portions I4 extend into the groove I3 of the screw II the saidscrew II and plate I0 are secured to each other and rotary movement'therebetween is permitted. Locking groove or grooves I8, Ill'l (Fig. 6)are disposed substantially at right angles to the shank of the screw II.Also, the screw I| has a spirally disposed vane I1 at one end portionand a screw head ||8 at the other end portion. Preferably the sdrew headls is adapted to 11e within the recess provided by the upturned portionsI 4 and thus provides a flush exterior surface which does not interferewith the air stream passing the external surface of plate I0. a

The second plate I9, which is the plate to which the plate I is to bereleasably secured or fastened, provides the aperture 20 which has adiameter which is substantially'greater than that of the shank of thescrew as clearly appears in Fig. 4. This permits sliding movement andaccommodation of the parts upon movement due to the weaving of thefuselage parts under strain in flight. Operatively positioned over theaperture 2li-is a spring 2l, preferably of U type, having its bowed orclosed end portion 22 secured to plate I9. This is preferablyaccomplished by welding a strip 23 over the portion 22, the strip havingraised portions 24, 24' to conform to and yet of a diameter as toyieldingly hold the spring 2|, but permit movement of the springmembers. Another strip 25 is preferably welded over the leg portions 26,26' of the U spring 2|, said strip having raised portions 21, 21,' ofsuch diameter as to yieldingly hold the leg portions 26, 26' and permitrotation of the spring members 2| through a considerable arc. Each ofthe leg portions 26, 26' has a two-fold movement in that each maysubstantially rotate in as well as slide endwise within one of theraised portions 21, 21' of the strip 25. This preferable two-foldmovement facilitates the interlocking of the fastener parts, the screwand the U spring 2l as the portions 28, 28' of the spring 2| may be putunder corresponding tension and the tension thus obtained may beemployed against screw 2| for locking purposes. I have provided `amechanism wherein the interlocking of the parts is accomplished byutilizing both the resiliency of the spring metal and a two-foldmovement of the spring parts. My mechanism provides a firmness ofholding 'which prevents vibration noises and at the same l i. e., a fiatspring as compared with a coil spring,

and the term is so herein employed. Also, the

function of the intermediate raised portions 28,

28 is two-fold and provides for the turningmovement within the springmeans (i. e., portions 28, 28' may be angularly moved and thus movedtoward and away from each other) upon moving the screw member Il intoand out of securing and unsecuring positions and also the raised or humpportions 28, 28"e1imina`te the necessity oli :spacer vmembers forproperly positioning the portions 28, 28 in. spaced relation as respectsthe .plate I9.

The intermediate portions 28, 28' `of the spring 2|, see Figs. 2, 3, and5, preferably lie in a plane which is in spaced or elevated relation tothe plane of the end portions of the U spring 2|. The intermediateportions 28,. 28' are joined tothe end portions 22 and 26, 26 byinclined sections 29, 29"

and 30, 36' having preferably 45 angles to the plane of the end portions22 and 26, 26'. The inclined portions 29, 29 and the bowed portion 22 ofthe spring 2| operate with strip 23 in holding the bowed endportion ofthe spring 2| in position. i

The mode of operation of a fastener embodying my invention is asfollows: Plate I6 is juxtaposed upon plate I9 and vane I1 is turned soand to draw said members 28, 28 toward the grooves I6, I 6 andincidentally to spread sidewise or separate the said members 28, 28',see dash line position of Fig. 4. The portions 26, 26 of spring 2|rotate in and retract in the raised portions 21, 21 of strip 25 untilthe portions 28, 28' are guided by the edge portions 34 (see Fig. 5) anddrop or move under the shoulders 35, 35 and into the locking grooves`l6,I6' whereupon the mid portions of the 'intermediate portions 28, 28

'are slightly depressed or displaced toward Vplate I9, see dash lines inFig. 5. Thus, the resiliency of the spring parts contacted by each sideof the vane I1 plus the slight rotating movement of the leg portions andplus the slight retraction of the leg portions, all combine infacilitating the fastening operation. The difference in the radialprojection of the portion 3| (see Figs. 1 and '1) of the locking groovesI6, I6' and that of the flattened portions 32 (see Fig. '1) of thelocking grooves I6, I6 permits the leg members of the spring to retractto rest substantially against the flattened portions 32. The shoulder 33on each end of a locking groove I6, I6' prevents further turning of thescrew I when moved into locking position. Also, the fastener isresiliently locked against release as the spring parts 28, 28 must bespread apart before the fastener can be released. Also substantialresistance to releasing movement o f screw I I is provided by engagementof cam surfaces 36, 36'- with the spring elements 28, 28'. Uponretractile movement of screw I I, these cam surfaces 36, 36' help tospread the spring elements 28, 28' and in so doing cause said springelements to react against shoulders 35, 35'. The entrance to the groovesI6, I6 formed between cam surfaces 36, 36' and shoulders 35, 35' is atan angle to the grooves I6, I6'. Thus the portions 28, 2B of the springmeans 2| will tend to follow the radially exterior edges of the members35, 35 and 36, 36' as the portions 28, 28 are entering and are leavingthe grooves I6, I6'. This involves spreadingof the portions v28, 28' asthey are entering and leaving the grooves I6, I6'.

The structure described and illustrated'thus obviously provides theplate member III, the other plate member I9, asprlng as one or both legs(structurally round) of spring 2Ithe portion orv portions 28, 28' whichproject awayfrom plate I9, the mounting means 23 which supports an endportion .of the spring and resists turning movement thereof, themounting means 21, 21 which permits sliding and rotary motion of anotherend portion of the spring means, and the screw member II which isconnected with plate III and has groove means I6, I6' engageable withportions 28, 28' of the spring means.

Obviously, changes may be made in the forms,

leg members round in cross section forming a.V U `shape in plan view andwith each leg member having a raised intermediate portion and which4spring member is disposed with the raised intermediate portions of theleg members registering with and projecting away from the aperture ofone plate member; securing means relatively nxedly securing the legmembers at their interconnected ends to said one plate member and. at

one side of the aperture therein: sleeve bearings i slidingly androtatively connecting the vunconnected end portions of the leg memberswith the said one plate member at the other side of the opening therein,whereby the unconnected end portions of the leg members may rotate andslide insaid sleeve bearings to permit bending and sidewise movement ofthe raised intermediate portions of said leg members; and a screwmembers rotatably mounted inthe aperture of the other said plate member,said screwmember cornprising a spiral vane portion'of "a size to beinserted between the said. raised portions of said leg members and toengage said portions upon angular movement, whereby upon angularmovement of said spiral vane portion the said intermediate portions willmove relative thereto' and the two plate members will move relativelytothe class described, the comi n .ber comprising two spaced andinterconnected ward each other, and leg member receiving f leg membersround in cross section forming a U vshape in plan view and with `eachleg member having a raised intermediate portion and which springmemberis disposed with the raised inter- -mediate portions of the legmembers registering with and projecting away from the aperture of oneplate member; securing means relatively ilxedly securing the leg membersat their interconnected ends to said one plate member and at one side oithe aperture therein; sleeve bearings slidingly4 and rotativelyconnecting the unconnected end -portions of the leg members with thesaid one plate member'at the other side of the opening therein, wherebythe unconnected end portions of the leg members may rotate and slide insaid sleeve bearings to permit bending and sidewise movement of theraised intermediate portions of said leg members; and a screw member'rotatably mounted in they aperture of the other said plate member,said-screw member com' prising a spiral vane portion of a size to be iniserted between the said raised portions of said leg members and toengage said portions upon angular movement, whereby upon angularmovement of said spiral vane portion the said intermediate portions willmove relative thereto and the two plate members will move relativelytoward each other, and a leg member receiving recessV providinga'shoulder angularly' disposed to the spiral vane portion back of whichthe intermediate portions may be urged 'and thereby retained.

MARION HUTTON GOWER.

nEFEnENCEs crrnn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Date Lumsden Dec. 12. 1944

